INRC Fall 2024 Water Research Seminar Series: Trends - October

Trends in Nutrient Loading From the Mississippi River Basin

Presenter: Lori Sprague, Hydrologist with U.S. Geological Survey in Denver, CO.

The USGS has monitored nutrients in the Mississippi River since the 1970’s. This long-term observational record is updated with new monitoring data annually, which is used to both forecast and understand the size of the hypoxic zone in the Gulf of Mexico each year as well as to track progress toward nutrient reduction goals set by the interagency Mississippi River/Gulf of Mexico Hypoxia Task Force. This presentation will delve into long-term trend assessment methods, results and possible causes.

Links to publications and resources in talk listed in order of appearance:

Stackpoole, S., Sabo, R., Falcone, J., and Sprague, L., 2021. Long-Term Mississippi River Trends Expose Shifts in the River Load Response to Watershed Nutrient Balances Between 1975 and 2017. Water Resources Research. 57: e2021WR030318

Robertson, D.M, and Saad, D.A., 2021. Nitrogen and Phosphorus Sources and Delivery from the Mississippi/Atchafalaya River Basin: An Update Using 2012 SPARROW Models. Journal of the American Water Resources Association. 57: 406-429.

USGS. 2012 SPARROW Models for the Midwest: Total Phosphorus, Total Nitrogen, Suspended Sediment, and Streamflow.

Murphy, J.C., Oelsner, G.P., Riskin, M.L., Wieben, C.M., Falcone, J.A., Marti, M.K., Follette, D.D., and Perkins, M.K., 2021, Water-quality and streamflow datasets used in Weighted Regressions on Time, Discharge, and Season (WRTDS) models to determine trends in the Nation’s rivers and streams, 1972-2017: U.S. Geological Survey data release, https://doi.org/10.5066/P9EZZ17E.

Houser, J.N., ed., 2022, Ecological status and trends of the Upper Mississippi and Illinois Rivers (ver. 1.1, July 2022): U.S. Geological Survey Open-File Report 2022–1039, 199 p., https://doi.org/10.3133/ofr20221039.